Food Safe Pathogen Surrogates for Rapid Verification of Sanitation in Food Processing Phase II Project Summary Food safety is a major issue with global impact. The CDC estimates that in the U.S. alone, 3,000 deaths are caused each year due to foodborne illnesses. It is estimated that a total of 76 million food-related illness cases occurred in 2013, with the U.S. spending $40 billion on treatment rather than prevention (Food Quality and Safety Magazine, 2015). Even though foodborne illnesses are often attributed to meat, dairy, and seafood, outbreaks due to contaminated produce have been on the rise (Harris et al., 2003; Lynch et al., 2009; Callejn et al., 2015). Fresh fruits and vegetables are mostly grown outdoors, leaving them susceptible to potential environmental contamination. Washing is the primary method employed by processors to ensure the safety of the produce they supply. However, washing is not always effective in removing microbial contaminants (decontamination). If the wash system is improperly managed, cross contamination can covert a small contamination event into an outbreak event. SafeTraces is proposing the development of SafeTracers?, a reliable, repeatable, continuous, fast, on-site test performed on finished product, to ensure appropriate washing by assessing decontamination and risk of cross-contamination of fresh produce. SafeTracers? are edible (Generally Recognized As Safe) microparticles, tagged with non-living, non-viable DNA, that behave like pathogens under wash conditions. They will enable validation, verification, and continuous monitoring of decontamination and cross-contamination in wash systems. SafeTracers? will be easily retrofitted on any wash system, and will be robust and simple to operate. During Phase II, we will compare SafeTracers? to prominent pathogens for their attachment, detachment, transfer, and inactivation on abiotic (glass and stainless steel) and on produce (spinach) surfaces. We will develop a simple workflow to sample finished product, measure SafeTracers? levels, and assess the effectiveness of the wash process, all in less than 30 minutes. Furthermore, we will develop a SafeTracers?-based method to assess the risk of E. coli cross contamination for leafy produce commodities in both one-pass and flume wash systems using chlorinated water wash. Finally, we will complete validation studies for the two SafeTracers?-based methods aimed at assessing the risks for insufficient decontamination and cross contamination in wash systems operating under validated conditions and processing leafy greens.